1. insertion sort
-----------------
initial array:
 7	39	20	11	16	5

39 doesn't need to be inserted:
 7   	39	20	11	16	5

20 is inserted:
 7   	20	39	11	16	5

11 is inserted:
 7   	11	20	39	16	5

16 is inserted:
 7   	11	16	20	39	5

5 is inserted:
 5   	7	11	16	20	39